Who proclaimed himself to be the muslim savior?

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.

Thomas jefferson was alarmed by the fierce debate over warning americans about its threat to national unity. 1.) slavery 2.) the powers of congress 3.) the missouri compromise 4.) escaped slaves

True or false? correlations can only be negative.